In general, vehicles have many electronic parts, and new electronic techniques are constantly being developed and applied to these vehicles, contributing to more electronic parts that only function when power is supplied to that electronic part. Accordingly, many wires are required to supply power to these electronic parts.
Conventionally, a fuse box was used to protect a large number of wires, where the wires, in the fuse box, were closely disposed to supply power to respective electronic parts. However, the fuse box caused many problems caused by assembly errors during the assembly process, as well as a compact disposition of terminals. In order to make up for problems, a junction box has been manufactured, where the wires in the fuse box are replaced with a printed circuit board and metal layers.
Further, electronic systems are becoming increasingly complicated since the number of functions has increased, as well as the number of electric modules in vehicles. Therefore, the junction box must serve as an electronic module having control and communication functions in addition to the existing power distribution function.
Hereinafter, conventional junction boxes will be described with reference to the annexed drawings.
FIGS. 1 and 2 are views illustrating conventional junction boxes.
As shown in FIG. 1, a conventional junction box includes a main board 10, on which fuses and relays are mounted. Further, a daughter board 20 is provided, which performs a control function. As such, the junction box is manufactured by connecting the two boards 10 and 20. Here, the daughter board 20 is mounted on the upper surface of the main board 10, as shown in FIG. 1, and connection between the two boards 10 and 20 is accomplished by using electrical connectors (not shown).
Further, the two boards 10, 20 of the junction box may be independently manufactured. That is, as shown in FIG. 2, another conventional junction box includes a first board 30, on which fuses and relays are mounted, and a second board 40 which performs a control function. Here, connection between the first board 30 and the second board 40 is accomplished by jumper pins (not shown).
In order to add control function with the power distribution function through the fuses and relays, the above conventional junction boxes respectively require additional boards, as shown in FIGS. 1 and 2. However, it is difficult to accommodate electronic parts that perform a control function within a board having limited size. Additionally, when the two boards are used, manufacturing costs of the junction boxes is increased. Size and weight of the junction boxes are increased as well, thus generating increase in the overall volume and weight of a vehicle. Further, installation of connectors to connect the junction boxes to external terminals is hampered by many restrictions.